Power supply apparatus and components thereof (thermal exchange)

ABSTRACT

A battery assembly comprising a thermal exchange device and a plurality of batteries arranged into a plurality of battery groups is disclosed. The thermal exchange device comprises a thermal contact surface which is in thermal contact with a heat transfer network, and a thermal exchange surface which is configured to perform heat exchange. The heat transfer network comprises the plurality of inter-battery connectors which are in electrical contact with battery terminals of the batteries forming the battery assembly. The inter-battery connectors are in physical and thermal contact with the thermal contact surface of the thermal exchange device to facilitate transfer of heat from the battery terminals to the thermal contact surface and are electrically insulated from the thermal exchange surface or the thermal exchange device.

FIELD OF DISCLOSURE

The present disclosure relates to power supply apparatus, and moreparticularly, to power supply apparatus having batteries and componentsof such power supply apparatus. The disclosure also relates to batteryassemblies and components for power supply apparatus.

BACKGROUND

Storage power devices such as batteries have become the main powersource of many vehicles and equipment. Power supply apparatus havingbatteries as a stored power source are beneficial and advantageous. Forexample, power supply apparatus having a stored power device can inputpower from the mains for storage during non-operating times and tooutput power during operating times when power supply is required fromthe power supply apparatus.

With ever-increasing power requirements, power supply apparatus isrequired to have a higher energy storage capacity and compactness.Compactness is usually achieved by using batteries having a higherenergy storage density and by having batteries or battery cells moreclosely packed together. However, batteries having a higher energystorage density, for example, lithium-ion batteries, are explosionprone.

SUMMARY OF DISCLOSURE

A battery assembly comprising a thermal exchange device and a pluralityof batteries arranged into a plurality of battery groups is disclosed.The battery group comprises a plurality of batteries in parallelconnection and the battery groups are connected in series by a pluralityof inter-battery connectors. The thermal exchange device comprises athermal contact surface which is in thermal contact with a heat transfernetwork, and a thermal exchange surface which is configured to performheat exchange. The heat transfer network comprises the plurality ofinter-battery connectors which are in electrical contact with batteryterminals of the batteries forming the battery assembly. Theinter-battery connectors are in physical and thermal contact with thethermal contact surface of the thermal exchange device to facilitatetransfer of heat from the battery terminals to the thermal contactsurface and are electrically insulated from the thermal exchange surfaceor the thermal exchange device.

A power supply apparatus comprising a main housing, a thermal exchangearrangement and battery management circuitry, and a battery assemblyaccording to the disclosure is disclosed.

Batteries forming the battery assembly are electrically interconnectedby a plurality of inter-battery-group connectors. For example, thebatteries are interconnected by inter-battery-group connectors to form aplurality of serially connected battery groups each comprising aplurality of batteries in parallel connection. For example, two adjacentbattery groups are interconnected by an inter-battery-group connectorand each inter-battery-group connector comprises a plurality ofinter-battery connectors in series. For example, three adjacent batterygroups are interconnected by two inter-battery-group connectors.

The battery assembly comprises a heat transfer network which is inthermal and electrical connection with battery terminals of the batteryassembly and a thermal exchange device which is in thermal connectionwith the heat transfer network but which is electrically insulated fromthe heat transfer network.

The main housing comprises a battery compartment in which the batteryassembly is held.

The thermal exchange arrangement is configured to facilitate exchange ofheat across a boundary or across a partition panel of the batterycompartment and comprises a thermal exchange device.

The thermal exchange device comprises a thermal contact surface which isin thermal contact with a heat transfer network and a thermal exchangesurface which is configured to perform the exchange of heat; and

The heat transfer network comprises the plurality of inter-batteryconnectors.

The inter-battery connectors are in physical and thermal contact withthe thermal contact surface of the thermal exchange device to facilitatetransfer of heat from the battery terminals to the thermal contactsurface and is electrically insulated from the thermal exchange surfaceor the thermal exchange device.

DESCRIPTION OF FIGURES

The present disclosure is described by way of example and with referenceto the accompanying figures, in which:

FIGS. 1A and 1B are perspective views of an example power supplyapparatus according to the present disclosure,

FIG. 1C is a longitudinal cross-sectional view of the power supplyapparatus of FIG. 1A taken along the main longitudinal axis L-L′,

FIG. 1D is a schematic diagram showing example compartmental layout ofthe power supply apparatus,

FIG. 2 is an exploded view showing example major components of the powersupply apparatus of FIG. 1A,

FIG. 2A is a perspective view of the power supply apparatus exposing thebattery assembly,

FIG. 2B is a perspective view of an example base plate showing heatconductive tracks,

FIGS. 3A and 3B are, respectively, perspective and front views of anexample inter-battery-row connector comprising an array of exampleinter-battery connectors,

FIG. 3C is an enlarged view of the circled portion (A) of theinter-battery row connector of FIG. 3A,

FIGS. 4A and 4B are perspective views of an example battery tray of thepower supply apparatus,

FIG. 4C is a plan view of the battery tray of FIG. 4A,

FIGS. 4D and 4E are enlarged views of the circled portions (B, C) of thebattery tray,

FIG. 5 shows a combined battery tray formed by latching of two batterytrays of FIG. 4A,

FIG. 5A is an enlarged view of the circled portion (D) of the combinedbattery tray of FIG. 5 , showing interfaces between two battery trays,

FIG. 6 shows an example battery assembly according to another aspect ofthe present disclosure,

FIG. 6A is a cross-sectional view of the example battery assembly ofFIG. 6 , taken alone a plane orthogonal to the battery axes,

FIG. 7A shows an example sub-assembly of the battery assembly of FIG. 6,

FIG. 7B is an exploded view of the sub-assembly of FIG. 7A,

FIG. 7C shows interconnection of two rows of batteries by an inter-rowconnector,

FIG. 8 is a perspective view of an example inter-row connector,

FIG. 9 is a perspective view of another example inter-row connector, and

FIG. 9A shows an enlarged view of the circled portion (E) of FIG. 9 .

DETAILED DESCRIPTION

An example power supply apparatus 10 of the present disclosure comprisesa battery assembly 100, management circuitry and a main housing 200inside which the battery assembly 100 and the management circuitry 300are received, as depicted in FIGS. 1A, 1B, 1C, 1D, 2, 2A, 2B, 3A, 3B,3C, 4A, 4B, 4C, 4D, 4E, 5 and 5A. The battery assembly 100 comprises aplurality of batteries 102 which are usually rechargeable batteriesorganized into a plurality of battery groups.

The main housing 200 comprises a plurality of compartments, for example,a main compartment and a fan compartment, as depicted in FIG. 1D. Themain compartment is partitioned into a battery compartment 106 insidewhich the battery assembly 100 is received, a circuitry compartment 104in which the management circuitry is received, an air compartment 400,and functional compartments which may be useful or beneficial. The fancompartment 500 is formed at a longitudinal end of the main housing 200and an air-moving arrangement is installed inside the fan compartment.

The main housing 200 may be formed from metal parts, parts of strongplastics or a combination of both metal and strong plastic parts. Themain housing may comprise a plurality of housing portions. For example,the main housing may comprise a main compartment housing portion and afan compartment housing portion. The main compartment housing may bepartitioned into a plurality of functional compartments.

The main housing comprises a first main housing portion (“first portion”in short), a second main housing portion (“second portion” in short),and a peripheral main housing portion (“peripheral portion” in short)interconnecting the first portion and the second portion. The firstportion is on a first axial end and has an inward-facing major surface(“first major surface”). The second portion is on a second axial end andhas an inward-facing major surface (“second major surface”) which has afacing orientation directly opposite to that of the first major surface.The example main housing 200 comprises a top portion 202 as an examplefirst portion, a bottom portion 204 as an example second portion and aperipheral portion 206 interconnecting the top portion and the bottomportion which cooperate to define the main compartment housing. Theperipheral portion extends in an axial direction Z between the bottomportion and the top portion to surround and define the main compartment.The peripheral portion has a first end which is a first longitudinal end210 in this example and a second which is a second longitudinal end 220in this example. The first longitudinal end 210 and the secondlongitudinal end 220 respectively defines a first longitudinal end and asecond longitudinal end of the main compartment.

The first longitudinal end 210 and the second longitudinal end 220 areopposite longitudinal ends of the main housing 200 are on a mainlongitudinal axis L-L′ of the main housing, which is also thelongitudinal axis of the main compartment and which defines a mainlongitudinal direction Y of the apparatus. The axial direction Z of theperipheral portion defines a main axial direction of the apparatus whichis orthogonal to the main longitudinal direction L.

The fan compartment housing portion is a longitudinal housing portionwhich projects away from the main compartment and extends in the mainlongitudinal direction of the main longitudinal axis L-L′ to define thefan compartment.

The circuitry compartment is on a first longitudinal end 210 of the mainhousing, the fan compartment is on a second longitudinal end 220 of themain housing, and the battery compartment is intermediate the circuitrycompartment and the fan compartment.

A plurality of peripheral devices is disposed on a front panel on thefirst longitudinal end 210 of the main housing. The peripheral devicesmay comprise input, output and control interfaces including a powerinput, a power output, data interfaces, and user-interfaces.

The apparatus is configured as a power supply module such that the powersupply module may operate as a standalone power supply or as a modularcomponent of a plurality of power supply module forming a larger scalepower supply.

The management circuitry comprises battery management circuitry andperipheral circuitry. The battery management circuitry may comprisebattery charging control circuitry, battery discharge control circuitry,battery conditions monitoring circuitry, battery safety controlcircuitry, and/or other useful circuitries. The peripheral circuitry maycomprise metering circuitry, telecommunication circuitry including adata communication frontend, switching control circuitry, remote sensingcircuitry, and other useful circuitries.

The example main housing 200 comprises a first main housing portion anda second main housing portion which cooperate to form the main housing.The example first main housing portion is an upper housing portion 230which comprises the top portion and the peripheral portion, and theexample second main housing portion is a lower housing portion 240 whichcomprises the bottom portion.

In example embodiments such as the present, the upper housing portion230 is shaped and configured to define a battery compartment and isformed of a thermally insulating material, such as hard engineeringplastics. The example upper housing portion is integrally formed form astrong engineering plastic material such as ABS and the batterycompartment is a closed compartment except where venting apertures 232are provided. In some embodiments, the upper housing portion may be of athermally conductive material, for example, steel, aluminum or othermetal. The upper housing comprises peripheral flanges which arecomplementary to peripheral flanges on the lower housing portion tofacilitate quick assembly.

The example lower housing portion 240 is formed as a metal casingportion. The metal casing portion comprises a metal plate portion 242, afan panel 244 on a longitudinal end, and peripheral flanges 246extending along its sides. The metal plate portion defines the bottomportion of the main housing as well as the floor 208 of the mainhousing. The fan panel extends orthogonally to the metal plate portionand defines a plurality of fan apertures which is aligned with fansmounted on fan-mounting frame formed on the upper housing portion topermit through passage of air through the fans mounted in the fancompartment.

The portion of the metal casing portion 242 which forms the bottomportion of the main housing is a stainless-steel plate which cooperateswith the upper housing portion 230 to form the main compartment and thefan compartment which is adjacent to and in fluid communication with theair compartment.

The battery assembly 100 is mounted on the main housing and held betweenthe top portion of the main housing and the air compartment.

The battery assembly 100 comprises a plurality of batteries which areelectrically interconnected. Batteries of the battery assembly may beinterconnected to form a plurality of parallel connected batteriesand/or a plurality of serially connected batteries. The battery assemblymay be arranged into one battery ensemble or a plurality of batteryensembles, and each battery ensemble is referred to as a battery group.A battery ensemble may comprise a plurality of batteries in parallelconnection and/or a plurality of batteries in serial connection. Thebatteries of the battery assembly are electrically interconnected by aplurality of inter-battery connectors. A plurality of inter-batteryconnectors may be connected in series to form an inter-ensembleconnector to connect an adjacent pair of battery ensembles.

The battery assembly may be arranged into one battery module or aplurality of battery modules. Each battery module comprises a pluralityof parallel connected battery groups and/or a plurality of seriallyconnected battery groups.

An example battery module comprises a first module portion having afirst module surface which defines a first module end and a secondmodule portion having a second module surface which defines a secondmodule end. The example battery module has a top portion as an examplefirst module portion and a top surface as an example first modulesurface which defines a top end as an example first end of the batterymodule. The example battery module has a bottom portion as an examplesecond module surface and a bottom surface as an example second modulesurface which defines a bottom end of the battery module, and aperipheral portion which extends in an axial direction between the topend and the bottom end. The top end and the bottom end are oppositeaxial ends of the battery module. The axial direction of the examplebattery module is parallel to the battery axes of the batteries of thebattery module. The axial direction of the example battery module isparallel to the main axial direction of the example main housing, butmay be at an angle or may be orthogonal to the main axial direction ofthe main housing in some embodiments.

An example battery module comprises a plurality of first batteryterminal contact tabs 112 which are distributed on the first portion ofthe battery module to form an exposed first module surface and acorresponding plurality of second battery terminal contact tabs 114which are distributed on the second portion of the battery module toform an exposed second module surface. A first battery terminal contacttabs is physically connected to a first battery terminal of a battery,for example by spot or laser welding. The first battery terminal of abattery has a first electrical polarity and a safety vent which isformed at or near the first battery terminal. The first battery terminalcontact tab 112 has a slit or an aperture and is exposed to a dischargechamber which is intermediate the battery module and the first portionof the main housing. The battery is held so that its safety vent isproximal to the first module surface and is unblocked by the firstmodule surface so that hot gaseous discharge emanating from the batterycan move freely from the first battery terminal to the first modulesurface and subsequently to the venting apertures 232 on the mainhousing. The safety vent of conventional batteries is typically formedproximal to the positive terminal of the battery in which case the firstbattery terminal is a positive terminal of a battery and the secondbattery terminal is a negative terminal of a battery. Where the safetyvent is proximal the negative battery terminal, the first batteryterminal will be the negative terminal and the second battery terminalwill be the positive terminal without loss of generality.

A second battery terminal contact tab 114 is physically connected to asecond battery terminal of a battery, for example by spot or laserwelding. The second battery terminal has a second electrical polaritywhich is opposite to the first electrical polarity. Where the firstbattery terminal is a positive terminal, the second battery terminal isa negative terminal and vice versa, The second module surface is anexposed module surface to facilitate physical and thermal connectionwith a thermal exchange device.

The peripheral portion of the battery module comprises a peripheral wallwhich surrounds the batteries of the battery module. The peripheral wallcomprises a peripheral surface which extends in the axial direction todefine the first portion and the second portion of the battery module.

The battery module is mounted on the main housing such that its firstsurface is proximal to the first portion and distal from the secondportion of the main housing and such that its second surface is proximalto the second portion and distal from the first portion of the mainhousing. The example battery module is mounted on the example mainhousing such that its top surface is proximal to the top portion of anddistal from the bottom portion of the main housing and such that itsbottom surface is proximal to the bottom portion and distal from the topportion of the main housing.

The battery module is maintained at an axial level with respect to thefirst surface of the main housing so that an axial separation ismaintained between the first surface of the battery module and the firstsurface of the main housing. This axial separation defines a dischargechamber so that gaseous discharge emanating from batteries of thebattery module can exit from the apparatus through venting apertures 232on the first surface of the main housing after travelling through thedischarge chamber. This axial separation is selected to be relativelysmall to facilitate effective monitoring of extreme battery conditions.The axial separation distance may be approximately between 0.2 cm and 2cm for the example battery arrangement, which is between 3% and 30% ofthe axial extent of a battery module of 18650 batteries. In general, theaxial extent is selected to be at or larger than 3%, 5%, 7%, 9%, 11% andsmaller than 20%, 25%, 30% of the axial extent of the battery module asa rule of thumb.

The venting apertures are in fluid communication with the dischargechamber and the number of venting apertures is significantly smallerthan the number of batteries of the battery assembly. The examplebattery assembly has over 250 batteries but only four venting apertures.Each venting aperture is equipped with a thermal sensor and the thermalsensors are connected to temperature monitoring circuits of the batterymanagement circuitry for monitoring temperatures of gaseous dischargesof the battery assembly. In order that the temperature of hot gaseousdischarge emanated from the batteries of the battery assembly does notdrop significantly before reaching the thermal sensors, the dischargechamber, or more particularly the top portion of the main housing isthermally insulated from the ambient to facilitate correct temperaturemonitoring. In this example, the first module surface is proximal to anddirectly facing the ceiling of the man housing, a plurality of ventingapertures is distributed on the top portion of the main housing, and thebattery module is maintained at an axial level below the ceiling of themain housing so that an axial separation is maintained between the topsurface of the battery module and the ceiling of the main housing. Insome embodiments, the first module surface is proximal to and directlyfacing the floor of the man housing, a plurality of venting apertures isdistributed on the bottom portion of the main housing, and the batterymodule is maintained at an axial level above the floor of the mainhousing so that an axial separation is maintained between the bottomsurface of the battery module and the floor of the main housing. Termssuch as upper and lower, top and bottom, above and below are used forease of reference with reference to how the apparatus is configuredduring use and is not meant to be restrictive. For example, theapparatus may be configured such that the battery axes which define themodule axis are horizontal or at an angle to the vertical and the termsupper and lower, top and bottom, above and below should be construedaccordingly and mutatis mutandis without loss of generality.

The example battery assembly comprises an example plurality of twobattery modules 101A, 101B which are mounted side-by-side and inabutment for maximal compactness. The battery modules may be mountedspaced apart where compactness is not required. The example batterymodules are mounted such that top surfaces of the component batterymodules are aligned on the same axial level and facing the ceiling ofthe main housing, the bottom surfaces of the battery modules are alignedon the same axial level and facing the bottom portion of the mainhousing, and the peripheral portions are laterally aligned so that thebattery assembly has a generally rectangular outline.

The battery assembly 100 comprises a base plate 120 which is mounted tothe bottom ends of the battery modules (or mounted to the bottom end ofthe battery module where the battery assembly has a single batterymodule) to form a bottom end of the battery module. The base plate 120partitions a portion of the main housing into an upper portion whichdefines the battery compartment and a lower portion which defines theair compartment. The base plate is fastened onto a peripheral flange ofthe main housing to form a substantially air-tight battery compartmentexcept at the venting apertures. The peripheral flange extends along theinner peripheral of the main housing and projects inwardly to form asealing flange so that when in cooperation with the base plate andfasteners distributed along the peripheral flange forms a substantiallyair-tight battery compartment. The base plate is in physical and thermalcontact with battery terminal tabs on the bottom end of the batterymodule but is electrically insulated from the battery terminal tabs.

The battery assembly is mounted on the main housing and is maintained atan axial level above the floor of the main housing. The floor of themain housing is an inward-facing surface on the bottom portion of themain housing.

The axial elevation of the battery assembly above the floor of the mainhousing defines the axial extent of the air compartment. The axialextent of the air compartment is larger than the axial extent of thedischarge chamber, for example, by 25%, 30%, 35%, 40%, or more.

The base plate 120 forms a bottom end of the battery module and has amajor surface which faces away from the battery module and forms abottom surface of the battery assembly. The air compartment is definedbetween the bottom surface of the base plate and the floor of the mainhousing.

The battery assembly 100 comprises a thermal exchange arrangement whichis to facilitate thermal exchange between the battery assembly and airinside the air compartment or ambient air. The thermal exchangearrangement comprises a thermal exchange device which is in thermalconnection with the battery modules and which has a thermal exchangesurface which is thermally exposed to the air compartment or the ambientair in embodiments where the main housing has no air compartment so thatheat exchange is with ambient air.

The example thermal exchange device of the present example comprises athermally conductive plate having a thermal contact surface 122 that isthermally connected to the battery terminals of the battery assembly bymeans of a heat transfer network and which has a thermal exchangesurface 124 which is exposed to air, for example air inside the aircompartment or ambient air where there is no air compartment. Thethermal contact surface and the thermal exchange surface areopposite-facing major surfaces of the thermally conductive plate.

The base plate 120 of the example battery assembly is a thermallyconductive plate which is to function as a thermal exchange device inthis example. To establish efficient thermal connection between thebattery terminals and the base plate, the battery contact tabs exposedon the bottom portion of the battery modules are joined to an uppersurface of the base plate by an electrically insulating thermalconductive medium such as a thermal conductive glue or preferablyelastomeric thermal conductive sheets or thermal conductive strips 130so that the base plate and the battery contact tabs are maintained inthermal connection but in electrical isolation from each other. Foroperations where the thermal exchange arrangement is to preventoverheating of batteries of the battery assembly, the upper surface ofthe base plate is for collecting heat from the batteries of the batteryassembly and is therefore a heat collection surface while the lowersurface of the base plate is a heat discharge surface for dissipatingheat into the air compartment. For operations where the thermal exchangearrangement is to warm up the batteries of the battery assembly to theiroperation temperature range, the operation reverses such that the lowersurface of the base plate becomes a heat collection surface to collectheat from the air compartment and the upper surface of the base platebecomes a heat discharge surface for dissipating heat into thebatteries.

The air compartment is an air chamber which is in fluid communicationwith the fan compartment on one longitudinal end and in fluidcommunication with ambient air on another longitudinal end which isdistal to the fan compartment. So that ambient air can be freely drawninto the air compartment for thermal exchange, the circuitry compartmenthas a lower surface 250 which is substantial flush with the base plateto form a through air-passageway between the first longitudinal end ofthe main housing and the entrance to the air compartment.

In example embodiments such as the present, the base plate 120 isphysically and thermally connected to battery contact tabs on the bottomsurface of the battery module to ensure good thermal contact and goodthermal connection between the battery module and the base plate. Theexample base plate 120 is a metal plate having a plurality of contacttracks 126. The contact tracks are an integral part of the metal plateand adjacent contact tracks are isolated and insulated. Each track isthermally connected to a row of batteries by means of a correspondingshaped thermal connector strip 130. An example base plate is formed froma composite base board having a composite structure similar to thestructure of a composite board for forming a printed circuit board,except that the base board has an insulted layer formed on a metalsubstrate rather than a metal layer formed on an insulator substrate.The example base plate has an aluminum plate substrate and an electricalinsulating coating on the plate substrate. The contact tracks may beformed by masked imprinting and etching so that the contact tracksremain and appear as printed metal tracks on a metal substrate aftermasked removal of the insulating layer on top. The thermal contacttracks are mutually isolated and mutually insulated tracks. Adjacentcontact tracks are separated by and/or surrounded by insulating trackswhich form insulating gaps. Each track is elongate and has a zig-zagprofile on each of its long edges to follow the zig-zag outline ofbattery compartments forming a battery receptacle row. The examplezig-zag profiles on the long sides of an example contact track aresymmetrical about a longitudinal axis of the contact track, which isalso a center axis of the contact track. The base plate is to functionas a heat sink to sink heat which is built-up or developed in thebattery assembly and to function as a heat dissipator to dissipate heatinto the air compartment. To enhance heat dissipation rates, heatdissipating protrusions, such as fins or distributed protrusions may beformed on the underside of the base plate. The underside of the baseplate is a thermal exchange surface of the base plate which is exposedto the air compartment and which is in thermal contact with air insidethe air compartment or ambient air. The thermal exchange surface is tofunction as a heat dissipation surface when arrange to dissipate heatfrom the battery compartment.

The metal plate which forms the bottom portion of the main housingfurther helps to enhance heat dissipation rate.

The example thermal connector strip may be an elastomeric thermalconnector, for example, an elastomeric thermal connector made of anon-silicone thermal interface material. products of the F-CO™ seriesavailable from Furukawa are an example of thermal conductive mediumsuitable for this purpose.

In the present example, battery contact tabs forming the top surface ofthe battery assembly are contact tabs which are physically joined topositive battery terminals of batteries of the battery assembly, andbattery contact tabs forming the bottom surface of the battery assemblyare contact tabs which are physically joined to negative batteryterminals of batteries of the battery assembly. The battery contact tabsmay be physically joined by spot welding, laser welding or other metaljoining techniques.

The base plate is thermally mounted to the negative battery terminalsthrough battery contact tabs on the bottom surface of the battery moduleto take advantage of the larger end surface area of a negative batteryterminal of a cylindrical battery (compared to the end surface area of apositive battery terminal) to enhance better thermal dissipation fromthe batteries to the base plate, which is to function as a heat sink orheat dissipating surface in the example embodiment.

In the example apparatus, the top and peripheral portions of the mainhousing cooperate with the base plate to define the battery compartment,and the bottom portion of the main housing cooperate with the base plateto define the air compartment. The battery compartment is a closedcompartment having the venting apertures as the only air outlets sogaseous discharge from the battery assembly can only exit from theventing apertures which are on the top portion of the main housing. Theair compartment is preferably a closed chamber having an air inlet onone longitudinal end and an air outlet on the other longitudinal end sothat ambient air drawn into the air compartment has to travel along theentire span of the air compartment for good thermal exchange.

An array of electrical fans is mounted on the fan compartment housing toform an example air-moving arrangement. The array of fans extendstransversely to the longitudinal axis and comprises an example pluralityof three axial fans and the fan axes are parallel to the longitudinalaxis of the main housing. The fans are arranged to move air out of theair compartment through the axial fans and to draw ambient air into theair compartment. In example embodiments, ambient air inlets are formedon a longitudinal end of the main housing which is distal to the fancompartment so that incoming ambient will traverse the entire length ofthe base plate before reaching the fan compartment to exit. In someembodiments, ambient air inlets may be formed on sides of the mainhousing which defines the air compartment.

During operations of the air-moving arrangement, air inside the fancompartment is drawn out of the fan compartment and exits from theapparatus through the fans. As a result, a low-pressure region is formedinside the fan compartment, and air inside the air compartment will bedrawn into the fan compartment due to pressure differences. As a resultof movement of air from the air compartment into the fan compartment, alow-pressure region is formed inside the air compartment and ambient airwill be drawn from outside of the apparatus into the air compartment toreplenish the loss of air from the air compartment.

The contact between the base plate and air inside the air compartmentwill result in thermal exchange between the base plate and air in theair compartment, and movement of air across the air compartment to theambient will result in transport of heat resident in the air of the aircompartment to outside of the apparatus.

When heat carrying air is moved across the air compartment andsubsequently moved out of the apparatus, the air compartment will bereplenished with newly drawn air of a lower temperature, for example, atambient air temperature, and continuation operation of the heat exchangeand removal process by operation of the air-moving arrangement willhopefully cool down the battery assembly rapidly to prevent adverse andcontagious heat built-up inside the battery assembly and preventcatastrophic battery melt-down.

The thermal exchange device is configured to collect heat frombatteries, and more specifically from interior of batteries, of thebattery assembly. To facilitate collection of heat from interior of thebatteries, a heat collection and transfer network (heat transfer networkin short) which thermally interconnects the electrodes of the batteriesand the thermal exchange device is provided. The example heat transfernetwork comprises heat collection terminals which are integrallyconnected to the first battery terminals of the batteries. Since thefirst battery terminal of a battery is always a good conductor of bothheat and electricity which is directly or integrally joined with abattery electrode to minimize resistance, a heat transfer network havingheat collection terminals which are in good thermal connection with thebattery terminals would facilitate efficient and rapid extraction ofheat from the interior of the batteries for dissipation to the ambientwhen the heat transfer network is thermally connected to the ambient,for example, by means of a thermal exchange arrangement.

The example heat transfer network comprises a plurality of inter-batteryconnectors of the battery assembly. An example inter-battery connectorcomprises a first battery terminal contact tab 112 (“first contact tab”in short), a second battery terminal contact tab 114 (“second contacttab” in short) and an inter-terminal tab 116 which interconnects thefirst contact tab and the second contact tab. The first contact tab isfor connection to a first terminal of a battery, the second contact tabis for connection to a second terminal of another battery which is inadjacency, and the inter-terminal tab is an inter-battery link whichinterconnects a pair of adjacent batteries.

An example inter-battery link comprises a first link portion 116 a, asecond link portion 116 b and an intermediate link portion 116 cinterconnecting the first link portion and the second link portion. Eachlink portion is a tab portion having geometry of a tap. A tab has amajor surface 116 d which is a flap surface, and the major surface of atab has an area which is significantly larger than (for example, 5times, 10 times, 15 times, 20 times or more as a convenient example) thearea of its minor surface 116 e. The terms tab and flap have sametechnical meaning herein and are interchangeably used.

The first link portion comprises a first metal flap portion whichintegrally interconnects the first contact tab and the intermediatemetal flap portion, and the first contact tab projects away from thefirst metal flap portion in a first projection direction. The secondlink portion comprises a second metal flap portion which integrallyinterconnects the second contact tab and the intermediate metal flapportion, and the second contact tab projects away from the second metalflap portion in a second projection direction which is opposite to thefirst projection direction. The first contact tab and the second contacttab are parallel and are separated by an axial separation distance equalto the axial height of one of the batteries being connected. The firstmetal flap portion and the intermediate metal flap portion areintegrally joined and have major flap surfaces which are coplanar. Thesecond metal flap portion and the intermediate metal flap portion areintegrally joined and have major flap surfaces which are coplanar.Portions are integrally joined or integrally connected if they arejoined together by fusion welding or if there formed from a single pieceof material as a convenient example.

In example embodiments such as the present, batteries of a batterymodule or a battery assembly are organized into a plurality of batterygroups and an adjacent pair of battery groups is interconnected inseries by inter-battery-group connector (“intergroup connector” inshort).

In example embodiments such as the present, a battery module comprises aplurality of battery groups arranged into a plurality of battery rows.Each battery row comprises a plurality of batteries in parallelconnection and the battery rows are connected in series.

A battery row and an adjacent battery row which form a pair of batteryrows of the battery module are interconnected by an inter-battery-rowconnector 110 (“inter-row connector” in short). The inter-row connectorcomprises an array of inter-battery connectors and the inter-batteryconnectors forming the array are distributed in a row direction to forma series of inter-battery connectors.

The inter-row connector comprises an array of first contact tabs, anarray of second contact tabs and an array of inter-terminal tabs. Thefirst contact tabs which form an array of first contact tabs aredistributed along the row direction and adjacent first contact tabs areseparated by an air gap. The second contact tabs which form an array ofsecond contact tabs are distributed along the row direction and adjacentsecond contact tabs are separated by an air gap. The inter-terminal tabsforming the array of inter-terminal tabs are interconnected at theirintermediate link portions to form an inter-terminal link whichinterconnects the array of first contact tabs and the array of secondcontact tabs and an array of inter-terminal tabs. The first tabs and thesecond tabs project in opposite projection directions and has contactsurfaces which are orthogonal to the row direction.

The inter-row connector comprises a plurality of first metal flapportions which are distributed along a row direction to form a row offirst metal flap portions, a plurality of second metal flap portionswhich are distributed along the row direction to form a row of secondmetal flap portions, and a plurality of intermediate metal flap portionswhich are distributed along the row direction to form a row ofintermediate metal flap portions. The first metal flap portion and thesecond metal flap portion are respectively the first link portion andthe second link portion in this example.

The first metal flap portions of an example inter-row connector aredistributed along the row direction to form a plurality of metal flapswhich extends orthogonally to the row direction between the intermediatemetal flap portions and the first contact tabs.

The second metal flap portions of the example inter-row connector aredistributed along the row direction to form a plurality of metal flapswhich extends orthogonally to the row direction between the intermediatemetal flap portions and the second contact tabs.

The first metal flap portions and the second metal flaps are alternatelydisposed in the row direction so that a first metal flap portion isintermediate a pair of adjacent second metal flap portions and a secondmetal flap portion is intermediate a pair of adjacent first metal flapportions.

Adjacent first metal flap portions of an inter-row connector areseparated by an interdigital separation distance and the interdigitalseparation distance between immediately adjacent first metal flapportions of an interrow connector are uniform wherein the width of thefirst metal flap portion is uniform. The interdigital separationdistance of the first metal flap portions of an inter-row connector isdependent on the width of the second metal flap portions and may becomparable to or larger than the dimension of the battery in the rowdirection.

Adjacent second metal flap portions of an inter-row connector areseparated by an interdigital separation distance and the interdigitalseparation distance between immediately adjacent second metal flapportions of an inter-row connector are dependent on the separationdistance of adjacent batteries and are uniform wherein the width of thesecond metal flap portion is uniform. The interdigital separationdistance of the second metal flap portions of an inter-row connector isdependent on the width of the second metal flap portions and may becomparable to or larger than the dimension of the battery in the rowdirection.

The first metal flap portions and the intermediate metal flap portionscooperate to form a first metal grating. The second metal flap portionsand the intermediate metal flap portions cooperate to form a secondmetal grating. The first metal flap portions, the second metal flapportions and the intermediate metal flap portions cooperate to form amain metal grating. Each of the metal gratings may be flexible and maybe exposed so that its major surfaces are non-thermally insulated andnon-electrically insulated. The intermediate metal flap portions of aninter-row connector are integrally connected to extend along the rowdirection to define the dimension of the inter-row connector in the rowdirection.

The intermediate metal flap portions of an inter-row connector areintegrally connected to extend along the row direction to define thedimension of the inter-row connector in the row direction.

The example inter-row connector comprises an elongate row tab 118 whichis a row link extending in the row direction to interconnect the firstmetal flap portions and the second metal flap portions of theinter-battery connectors forming the inter-row connector.

The metal flap portions have major flap surfaces which are parallel tothe row direction.

An example inter-row connector is formed from a single flexible metalsheet and comprises a plurality of flexible tab portions.

An example battery module comprises a battery tray 140 (or tray inshort), a plurality of batteries 160 held on the battery tray and aplurality of inter-row connectors interconnecting the batteries. Theinter-row connector is for connecting battery terminals of batteries inone receptacle row with battery terminals of batteries of an abuttingadjacent receptacle row. In example embodiments, where a battery modulehas a plurality of M receptacle rows, there is a corresponding pluralityof M inter-row connectors.

Where an adjacent pair of receptacle rows of a battery module has aplurality of N battery receptacles, the inter-row connector comprises aplurality of N inter-battery connectors which are interconnected by arow link. Each inter-battery connector comprises a first contact tab, asecond contact tab and an intermediate link which interconnects thefirst contact tab and the second contact tab. As the first contact taband the second contact tab are terminal contact tabs for connecting todifferent batteries, the intermediate link is also an inter-batterylink. A contact tab herein is a battery terminal contact tab unless thecontext requires otherwise. An example first contact tab is forconnection to a first terminal of a battery of a receptacle row and anexample second contact tab is for connection to a second terminal of acorresponding battery on an adjacent receptacle row. The example firstcontact tab projects away from the intermediate link and extends away,for example, orthogonally away, from the adjacent receptacle row. Theexample second terminal projects away, for example, orthogonally awayfrom the intermediate link and extends away from the first contact tab.The first contact tab and the second contact tab are parallel and has anaxial separation equal to or comparable to the length, axial extent, orheight (which is 65 mm for an 18650 sized battery) of the cylindricalbattery. The example intermediate link is an elongate metal flap havingmajor surfaces which are parallel to the row direction of the receptaclerow and which are parallel to the battery axes of the correspondingbatteries which the inter-battery connector connects. The metals flapsforming the intermediate link extends in an air gap between the firstand second terminals of the corresponding batteries. Because the contacttabs are in physical and electrical connection with the batteryterminals of the corresponding batteries, heat built up in the batterieswill be transferred to the inter-row connector and then to the baseplate. The inter-row connector is configured to have a high surface areato volume ratio and is made of a good thermal and electrical conductorto enhance heat transfer to the base plate and good heat dissipation.The base plate and the interrow connectors are configured to form a heattransfer network whereby heat generated by batteries of the batterymodule is transferred to the base plate through the inter-rowconnectors. The heat transfer network comprises a thermal transfermatrix comprising rows of thermal conductive flaps which are thermallyjoined with the base plate. The thermal conductive flaps extend in anaxial direction along the length of the batteries.

To promote efficient transfer of heat from interior of batteries of thebattery assembly to the base plate for subsequent dissipation into theair compartment, the second contact tab, which is permanently joined tothe base plate by a heat transfer interface medium, has dimensionscomparable to, equal to or slightly larger than the second terminal ofthe battery in contact.

The example inter-row connectors of the present disclosure areconfigured to have a high surface area to volume ratio to function as agood heat dissipator.

A battery tray 140 of the present disclosure comprises a plurality ofbattery receptacles 142 for holding a corresponding plurality ofbatteries, so that each battery has its own battery receptacle. Thebattery receptacles of a battery tray are organized into a plurality ofM receptacle rows. Each receptacle row (or row in short) comprises aplurality of N battery receptacles and extends along a receptacle rowaxis which defines a receptacle row direction X. Each battery receptaclehas a receptacle axis, which is a center axis of the battery receptacledefining an axial direction of the receptacle. The receptacle row axisof a receptacle row is formed by joining the receptacle axes of thebattery receptacles of that receptacle row. The battery receptaclesforming a receptacle row are distributed along the receptacle row axisof the receptacle row between a first row-end and a second row-end. Thefirst row-end is a first lateral end on which a first end-receptacle (orfirst receptacle) is located and the second row-end is a second lateralend of the receptacle row on which a second end-receptacle (or lastreceptacle) is located.

The battery tray comprises a plurality of immediately abuttingreceptacle rows and the immediately abutting receptacle rows areparallel to each other. The receptacles rows forming a battery tray aredistributed in a distribution direction Y. The distribution directionmay be orthogonal to the receptacle row direction X, but can be an angleto the receptacle row direction. The receptacle rows may be distributedso that spacings between immediately adjacent receptacle rows, which areabutting adjacent receptacle rows, are same or uniform. The receptaclerows forming a battery tray may have same number or different numbers ofbattery receptacles.

The example battery tray of FIG. 4 comprises an example plurality offourteen receptacle rows (M=14). The example plurality of receptaclerows forming the example battery tray comprises first receptacle row142_01, last receptacle row 142_14, and an example plurality of 12intermediate receptacle rows 142_02, . . . , 142_13, which are uniformlydistributed between the first receptacle row and the last receptaclerow. The first receptacle row is a first end row and the last receptaclerow is a second end row of the battery tray. The first end row and thesecond end row cooperate to define the longitudinal ends of the batterytray in the distribution direction Y. Each receptacle row of the batterytray comprises an example plurality of nine battery receptacles (N=9).The battery receptacles in a receptacle row are identified by a numbersystem for ease of reference. In the number system, the position numberof a battery receptacle is with respect to the first end (or firstrow-end), so that the first receptacle is one which is on the first end,the second receptacle is one next to the first, the third receptacle isone next to the second, . . . , and the last receptacle (or the ninthreceptacle in this example) is one on the second end (or secondrow-end).

The receptacle rows are organized such that immediately adjacentreceptacle rows are parallel but laterally offset and alternatereceptacle rows are laterally aligned. With this lateral offsetconfiguration, each of the lateral boundaries of the battery tray has azig-zag profile or a serrated profile. The serrated profile on a firstlateral side 146 a is formed by end walls of the first end-receptaclesand the serrated profile on a second lateral side 146 b is formed by endwalls of the second end-receptacles. The extents of lateral offsetbetween adjacent receptacle rows are same in this example battery trayso that each lateral boundary comprises a plurality of indentations andprotuberances of uniform lateral extent. The example extent of lateraloffset is approximately half-width of the lateral extent (or width) of abattery receptacle so that three consecutive adjacent receptacle rowscooperate to define a half-battery receptacle 148 a on the first lateralside. Where the receptacle rows have same number of battery receptacles,three consecutive adjacent receptacle rows cooperate to define anotherhalf-battery receptacle 148 b on the second lateral side.Notwithstanding the zigzag boundaries, the example battery tray has agenerally rectangular shape which is cooperatively defined by the firstand last receptacle rows and the lateral protrusions on the lateralboundaries.

The example battery tray is organized so that odd-numbered rows arelaterally aligned with odd-numbered rows, even-numbered rows arelaterally aligned with even-numbered rows, and an odd-numbered row andan even-numbered row are laterally offset with respect to each other.When receptacle rows are aligned or laterally aligned, correspondingbattery receptacles on the aligned rows have their battery receptacleaxes aligned in a direction parallel to the distribution direction Y.Corresponding battery receptacles herein means battery receptacleshaving same receptacle position numbers with respect to a row end.

The example battery tray has an even number of rows of more than tworows such that the first receptacle row and the last receptacle row arelaterally off-set and the first receptacle row and the last-secondreceptacle row are laterally aligned. When receptacle rows are aligned,the first end-receptacles of the aligned receptacle rows have theirreceptacle axes on a line which is parallel to the distributiondirection Y. Where the receptacle rows have same number of batteryreceptacle, the second end-receptacles of the receptacle rows have theirreceptacle axes on a line parallel to the distribution direction Y. Whena battery tray has an odd number of rows of more than three rows, thefirst receptacle row and the last receptacle row are laterally alignedwithout loss of generality.

Each of the intermediate receptacle rows comprises a plurality of rowpassageways. Each row passageway passes through two adjacent receptaclerows and spans across all battery receptacles of the two adjacentreceptacle rows to define a row-channel. The row-channel is elongate andextends in a direction parallel to the row axis. An intermediate row ofthe battery tray comprises a first row-channel which is on a first sideof the row axis and a second row-channel which is on a second side ofthe row axis so that the row axis is parallel to and intermediate thefirst and second row-channels. The example first and second row-channelsare symmetrically disposed with respect to the row axis and isequidistant from the row axis of the intermediate row. An end receptaclerow (the first receptacle row, the last receptacle row) has a single rowpassageway which extends to pass through both the end receptacle row andan intermediate row in abutment with the end receptacle row (or end rowin short).

Each passageway has an end aperture on the first row-end, and/or an endaperture on the second row-end to facilitate external electrical contactbetween the connector which passes through the passageway.

The example battery tray is designed for holding prismatic batteries,for example, cylindrical rechargeable batteries. The example batteryreceptacles are customized for holding 18650 lithium-ion rechargeablebatteries, which are cylindrical rechargeable batteries widely used foroperation of electrical vehicles and having a rated voltage of about 3.6volts. An 18650 battery is a single-cell battery having a nominaldiameter of 18 mm and a nominal length of 65 mm. Where a battery tray isadapted for holding a single type of batteries, the battery receptaclesare designed so that the battery compartments for holding the batterieshave same (including substantially same) compartment dimensions. Fororderly designs, battery receptacles forming a receptacle row areuniformly distributed along the row direction so that the separationdistance between adjacent receptacle axes are uniform throughout the rowand have same dimensions. Since the battery receptacles form areceptacle row have same dimensions and have uniform separationdistance, receptacle rows having same number of battery receptacles havesame length. Where batteries of a battery assembly are single-cellbatteries, the inter-battery connector is referred to as intercellconnector without loss of generality.

A battery receptacle 142 (or “receptacle” in short) comprises a firstaxial end, a second axial end which is axially aligned with the firstaxial end, and an intermediate portion interconnecting the first axialend and the second axial end. The first axial end is an open end havingan end aperture which is large enough for a battery terminal to exposefor external contact but not large enough for a battery to leave. Thesecond axial end is an open end having an entry aperture which is largeenough for axial entry of a battery. The first axial ends of the batteryreceptacles define the top surface of the tray and the second ends ofthe battery receptacles define the bottom surface of the tray. Theintermediate portion comprises a peripheral wall having an inner surfacewhich surrounds a battery cell compartment. A plurality of spacing finsis formed on the inner surface of the peripheral wall. Each spacing finprojects from the peripheral wall and extends inwardly and the spacingfins cooperate to define an outer periphery of the battery cellcompartment. The battery cell compartment, or the outer periphery of thebattery cell compartment, is calculated to conform to the outline of theouter periphery of the battery so that a battery is received inside thebattery cell receptacle in a closely-fitted manner or with a very smallspacing between the battery and the outer periphery of the battery cellcompartment. The spacing fins are distributed around the inner surfaceof the peripheral wall to define a cylindrical compartment and to definean air gap between the battery and the peripheral wall to facilitateheat dissipation during operation of the power supply apparatus when thebattery generates heat. The battery cell compartment has across-sectional dimension of slightly larger than a diameter of 18 mm,say, 18.2-18.5 mm. In general, an air-gap of about or less than 0.5% oneach side would suffice. The air-gap dimension is to be adapted todepend on battery size and or capacity. For an 18650 battery, theair-gap fin is selected to be approximately 1 mm, but a range of between0.5-1.5 mm may be used.

The battery tray has a first surface (or first tray surface), a secondsurface (or second surface surface) and a peripheral wall (or trayperipheral wall) interconnecting the first surface and second surface.Each battery receptacle defines a battery cell compartment having acompartment axis which is parallel to or coaxial with the receptacleaxis. A corresponding plurality of battery cell compartments defined bythe plurality of battery receptacles of the battery tray are distributedwithin the peripheral wall of the battery tray. The peripheral wall hasa generally rectangular outline notwithstanding having serratedsidewalls. The first tray surface is defined by the first axial ends ofthe battery receptacles and is, more specifically, formed by anaggregate of the first axial ends of the battery receptacles and isorthogonal to the receptacle axes of the battery receptacle. The secondtray surface is defined by the second axial ends of the batteryreceptacles and is, more specifically, formed by an aggregate of thesecond axial ends of the battery receptacles and is orthogonal to thereceptacle axes of the battery receptacle. The tray peripheral wall isparallel to the receptacle axes of the battery receptacle. In exampleembodiments, the battery tray is formed of strong engineering plastics,for example, polycarbonate or ABS to withstand expected harsh operationconditions.

A battery receptacle 142 comprises a first sidewall portion 142 a, asecond sidewall portion 142 b, a third sidewall portion and a fourthsidewall portion which cooperate to form the peripheral wall of theintermediate portion surrounding the battery compartment.

The first sidewall portion and the second sidewall portion are oppositefacing sidewall portions on the row axis of the receptacle rowcontaining the battery receptacle and on opposite sides of thereceptacle axis. The first sidewall portion defines a first lateralboundary of the battery receptacle, the second sidewall portion definesa second lateral boundary of the battery receptacle, and the firstsidewall portion and the second sidewall portion cooperate to define thelateral extent (or width) of the battery receptacle. Lateral extentherein is an extent in the direction of the row axis.

Where a battery receptacle is one which is an intermediate batteryreceptacle in abutment with two adjacent battery receptacles of the samereceptacle row, each one of the first sidewall portion and the secondsidewall portion is a receptacle wall portion of the intermediatebattery receptacle which is shared by the intermediate batteryreceptacle and one of the abutting adjacent battery receptacles of thesame receptacle row. In other words, the first sidewall portion and thesecond sidewall portion of an intermediate battery receptacle areopposite facing receptacle sidewall portions which are shared by threeconsecutive battery receptacles on the receptacle row. The firstsidewall portion and the second sidewall portion are also partitioningwall portions which provide partitioning among three consecutive batteryreceptacle compartments on the receptacle row. Where a batteryreceptacle is an end-receptacle, i.e., one that is on a row end, one ofthe first sidewall portion and second sidewall portion is shared with anabutting adjacent battery receptacle.

The third sidewall portion and the fourth sidewall portion are sidewallportions on opposite sides of the row axis and on opposite sides of thereceptacle axis such that the receptacle axis of the battery receptacleand the row axis of the receptacle row containing the battery receptacleis intermediate the third sidewall portion and the fourth sidewallportion. Each one of the third sidewall portion and the fourth sidewallportion is a sidewall portion which interconnects the first sidewallportion and the second sidewall portion.

The example battery tray comprises a first tray end 144 a which is afirst end of the tray, a second tray end 144 b which is a second end ofthe tray, a first tray side which is a first lateral side 146 a of thetray, and a second tray side which is a second lateral side 146 b of thetray. The first side wall portion 142 a of a battery receptacle 142 is asidewall portion which is proximal to the first lateral side (and distalto the second lateral side) of the tray. The second side wall portion142 b of a battery receptacle is a sidewall portion which is proximal tothe second lateral side 146 b (and distal to the first lateral side) ofthe tray. The third side wall portion of a battery receptacle is asidewall portion which is proximal to the first tray end 144 a (anddistal to the second tray end). The fourth side wall portion of abattery receptacle is a sidewall portion which is proximal to the secondtray end 144 b (and distal to the first tray end).

The receptacle rows are distributed in parallel and in abutment betweenthe first tray end and the second tray end, comprising a first end row,a last end row and a plurality of intermediate rows between the firstend row and the last end row. The first end row is a receptacle row onthe first tray end and the last end row is a receptacle row which is onthe second tray end.

The battery tray has a first end wall which is a peripheral wall on thefirst tray end and a second end wall which is a peripheral wall on thesecond tray end. The first end wall is defined by sidewall portions (ormore specifically the third side wall portions) of the receptacles onthe first end row. The second end wall is defined by sidewall portions(or more specifically the fourth side wall portions) of the receptacleson the last end row. The first tray end comprises a flange portion whichprojects away from the first end wall. No flange portion is formed onthe second tray end so that the first and second ends can be identifiedmore easily. In some embodiments, a flange portion which projects awayfrom the second end wall may be formed. The flange portion is to sit ona corresponding flange formed on the main housing when assembled.

The battery tray has a first side wall which is a peripheral wall on thefirst tray side and a second side wall which is a peripheral wall on thesecond tray side. The first side wall is formed by sidewall portions (ormore specifically the first side wall portions) of the first receptaclesof the receptacle rows. The second side wall is formed by sidewallportions (or more specifically the second side wall portions) of thelast receptacles of the receptacle rows.

A plurality of conductor outlets is formed on the peripheral wall of thefirst tray side and/or the second tray side. The conductor outlet isformed as an axially extending slit portion on a side wall portion of areceptacle which defines part of the side wall of the tray. The slitportion is a continuation of a conductor passageway on a receptacle rowto permit a portion, for example, a tab portion, of an inter-rowconnector to protrude or pass through. The number of slit portionsrequired is equal to the number of inter-row connectors which is equalto the number of rows minus one.

A plurality of windows and a corresponding plurality of protrusions areformed on selected locations on the peripheral wall of the first trayside and/or the second tray side. The window is formed as an axiallyextending slot on a side wall portion of a receptacle which defines partof the side wall of the tray. The protrusion is formed as an axiallyextending bar which protrudes away from a side wall portion of areceptacle which defines part of the side wall of the tray. A window anda corresponding protrusion of an adjacent tray are complementary tofacilitate complementary engagement and latching of adjacent batterytrays to form a combined battery tray, as depicted in FIG. 5 . Thewindows and protrusions are disposed such that the first end and thesecond ends of the component trays are on opposite ends of the tray whencombined. This provides flexibility of tray combination so that thetrays can be combined to form a battery assembly having the same numberof rows as a single tray but a larger number of battery receptacles perreceptacle row, or smaller number of battery receptacles per receptaclerow.

A combined battery tray having the same number of battery receptaclesper receptacle row but a larger number of battery rows, for example, amultiple of the number of receptacle rows, although the component traysare still in side-by-side engagement or latching.

For the avoidance of doubt, the use of ordinal numbers such as first,second, third, fourth, etc., is only for convenience of reference anddescription and is not meant to indicate a degree of importance orsignificance, or necessary order or sequence, unless the contextotherwise requires.

Where the battery receptacle is an intermediate battery receptacle on anintermediate row, each one of the third sidewall portion and the fourthsidewall portion is a shared sidewall portion which is shared with twoabutting battery receptacles of an abutting adjacent receptacle row.More specifically, a third sidewall portion on one intermediate row is aalso part of the fourth sidewall portion of a first abutting adjacentbattery receptacle and part of the fourth sidewall portion of a secondabutting adjacent battery receptacle of first abutting adjacentreceptacle row; and a fourth sidewall portion on that intermediate rowis a also part of the third sidewall portion of a first abuttingadjacent battery receptacle and part of the third sidewall portion of asecond abutting adjacent battery receptacle of second abutting adjacentreceptacle row.

The peripheral wall of the intermediate portion of the example batteryreceptacle has the shape of a prismatic hexagon having the receptacleaxis as the center axis or the prismatic axis. Each of the firstsidewall portion and the second sidewall portion forms a wall of theprismatic hexagon which is orthogonal to the row axis and the firstsidewall portion and the second sidewall portion are directly oppositefacing. Each of the third sidewall portion and the fourth sidewallportion comprises two abutting sidewalls of the prismatic hexagon. Theexample battery receptacle has the shape of a regular hexagon such thatthe sidewalls of the hexagon have same length. The battery receptaclesare distributed resembling distribution of cells of a beehive, such thata typical battery receptacle is surrounded in abutment by 6 surroundingbattery receptacles and the sidewalls of the typical battery receptacleare shared with the 6 surrounding battery receptacles.

A typical battery receptacle of an intermediate row comprises a firstpassageway portion which is formed on the third sidewall portion and asecond passageway portion which is formed on the fourth sidewallportion. Each passageway portion is parallel to the row axis and isdefined by a first slit portion and a second slit portion. The slitportion 143 is formed on a sidewall of the hexagonal battery receptaclewhich for part of the third sidewall portion or part of the fourthsidewall portion. Each slit portion extends along a slit axis which isparallel to the receptacle axis and orthogonal to the row axis. Anintermediate battery receptacle on an intermediate row is a typicalbattery receptacle in the present context.

Slit portions on the third sidewall portions of the battery receptacleson an intermediate receptacle row forms an ensemble of slit portions.The ensemble of slit portions defines a first passageway which extendsacross all battery receptacles on the receptacle row to provide athrough passage for an inter-battery-row conductor.

Slit portions on the fourth sidewall portions of the battery receptacleson an intermediate receptacle row forms an ensemble of slit portions.The ensemble of slit portions defines a second passageway which extendsacross all battery receptacles on the receptacle row to provide athrough passage for an inter-battery-row conductor.

The battery receptacles on an end row have either a slit third sidewallportion or a slit fourth sidewall which forms a passageway portionthrough passageway. A flange is formed on one of the end rows andprojects away from the battery receptacles in a direction parallel tothe distribution axis.

The slit portions of each passageway portion begin from the second axialend of the tray and extends axially towards the first axial end for anaxial depth. Each passageway portion has an entry aperture defined bythe slit portions to permit a portion of the row link to enter thepassageway portion.

The plurality of windows and the corresponding plurality of protrusionscooperate to form a plurality of tray alignment devices. An alignmentdevice is formed on some of the end battery receptacles. The alignmentdevice comprises an axial protrusion and an axial slot which are formedon an end sidewall portion which is not shared with another batteryreceptacle. The end sidewall portion can be a first sidewall portion ora second sidewall portion. The axial protrusion protrudes away from theend sidewall portion along the row-axis direction and extends in anaxial direction which is on the row axis and parallel to the receptacleaxis. The axial slot has a slot axis which meets the row axis and whichextends in an axial direction parallel to the receptacle axis. The axialprotrusion and the axial slot extend for half or less than the height ofthe sidewall portion. Height of a sidewall portion is its dimensionmeasured in a direction parallel to the receptacle axis. An axialthrough bore is formed on the axial protrusion to permit a pin topassthrough to enter onto the bored protrusion of another battery traywhen the battery assembly comprises more than one battery tray ofbatteries.

To assemble a battery module, the first contact tabs of an inter-rowconnector is inserted into a receptacle row from the second axial endand moved towards the first axial end until the first contact tabs hasreached the first axial end of the battery receptacles.

When the first contact tabs have reached its designated position, therow tab 118 of the inter-row connector is in place and seats inside apassageway, with its major surfaces facing the batteries ininterconnection and parallel to the battery axes. The row tab penetratesthrough the row of battery receptacles along a path defined by thepassageway and has an end tab portion 118 a which projects out of thebattery tray. When the row tab is in position, the first contact tabsare in receptacles of one receptacle row and the second contact tabs arein receptacles of another receptacle row which share the row tabpassageway with the receptacle row.

When the first contact tabs have reached the first axial end, the secondcontact tabs will be on the second axial end of the battery receptacles.

After all the inter-row connectors are in place, the batteries areinserted into the battery receptacles and the battery terminals will beelectrically connected with the corresponding contact tabs, for example,by fusion welding such as laser welding or spot welding to integrallyconnect the battery terminals and the corresponding contact tabs.

Where a battery comprises a plurality of battery modules, a plurality ofbattery trays of the corresponding plurality of battery modules areplaced side by side and inter-row connectors having row tabs which arelong enough to pass through the battery modules are placed inside thebattery trays and similar steps are to be performed.

In some embodiments, the individual battery modules may be assembledseparately, mounted on the main housing and then having the inter-rowconnectors electrically joined together.

After the battery module or battery modules have been assembled, thebase plate is attached to a bottom surface of the battery module(s) bymeans of an electrically insulating thermal contact medium to completethe construction of a thermal exchange assembly of the power supplyapparatus to facilitate effective thermal exchange between the heattransfer network and the base plate. The heat transfer assemblycomprises the inter-row connectors of the battery assembly and the baseplate as an example of a thermal exchange device. Where the batteriesare not connected by inter-row connectors, the heat transfer assembly isformed by an ensemble of individual inter-battery connectors and thethermal exchange device without loss of generality. In this example, thesecond battery terminal is a negative terminal of a battery and thenegative terminals of the batteries of the battery assembly are weldedwith the second contact tabs which are thermally joined with the baseplate. When a battery module is assembled, a battery is received insidea battery receptacle, for example, with its battery axis aligned withthe receptacle axis, the first contact tab is proximal to and exposed onthe first module surface and is in physically and electrically joinedwith the first battery terminal, the second contact tab is proximal toand exposed on the second module surface and is in physically andelectrically joined with the second battery terminal, and theinter-battery link of an inter-battery connector is inside the batteryreceptacle and extends between the first contact tab and the secondcontact tab. An inter-battery link extends between two adjacentreceptacles rows and between adjacent receptacles on adjacent receptaclerows. The first link portion of an inter-battery connector is inside thereceptacle of one battery while the second link portion of theinter-battery connector is inside the receptacle of another battery. Theintermediate link portion or the row link is in both receptacles. A rowlink portion is held in position by a passageway formed on the batteryreceptacle and is held on an axial level above an axial end by the slitportion of the battery receptacle. The axial extent of the example slitportions which define a passageway portion on a battery receptacle hasan example length of 22 mm, which is about one-third of the axial extentof a typical battery receptacle of the example tray. In general, a slitportion having an axial extent of more than 20%, 25%, 30% and less than35%, 40% of the axial length of the battery would provide a goodbalance. The link portions of an inter-battery connector are configuredto extend inside the air gap portion of the battery receptacle which isdefined by the spacing fins and the battery. The first link portion andthe second link portion are laterally displaced since abuttingreceptacles on abutting receptacle rows are laterally displaced.

In example embodiments such as the present, the first link portionextends axially inside a battery receptacle and the second link portionextends axially inside an adjacent battery receptacle on an adjacentreceptacle row. The example first link portion extends and the row linkare orthogonal to each other, defining a T-section inside the batteryreceptacle. The example second link portion extends and the row link areorthogonal to each other, defining another T-section inside a batteryreceptacle. A T-section formed by two mutually orthogonal tab-portionsforms a more stable connector structure inside a battery receptacle.Each battery receptacle has either a first link portion or a second linkportion, but not both.

To mitigate risks of electrical contact between adjacent batteryterminal contact tabs on abutting receptacle rows while minimizing spacebetween adjacent rows, adjacent rows of contact tabs may be partiallyinsulated electrically. For example, an electrical insulation medium maybe applied on a portion of the second tab which is in abutment with theintermediate link portion of an inter-battery connector. In exampleembodiments, an electrically insulating (preferably non-thermallyinsulating) tape may be applied across a row of second contact tabs tocover the portions of the second contact tabs which are proximal theintermediate link portions to mitigate potential risks of electricalcontact between second contact tabs of abutting receptacle rows. Sincethe first contact tabs usually have smaller surface dimensions than thesecond contact tabs, electrical insulation may not be necessary foradjacent rows of first contact tabs.

Referring to FIG. 5 , the example battery tray comprises an exampleplurality of M=14 receptacle rows and an example plurality of N=9battery receptacles per row. The two battery modules forming the examplebattery assembly are mounted side-by-side with the rows aligned so thateach row of the battery assembly comprises N=18 batteries. The inter-rowconnector has N first terminal tabs and N second terminal tabs. Whilethe inter-battery connectors are distributed in the row direction andsuch that adjacent inter-battery connectors have a generally uniformseparation distance, the separation distance between two immediatelyadjacent inter-battery connectors on two adjacent battery trays islarger than the separation distance between two immediately adjacentinter-battery connectors on the same battery tray. With the M rows ofbatteries in series connection, the battery assembly has an outputvoltage equal to MV_(b), where V_(b) is the voltage of each battery row.For an 18650 battery, V_(b) is taken as 3.6V and the battery assemblyhas a voltage of about 50.4V.

When the inter-row connectors and the batteries are duly put in place inthe trays and battery assembled, batteries of a receptacle row are inparallel electrical connection and the battery rows or adjacent batteryrows are serially connected. When so assembled, the first batteryterminals of the batteries in a row are connected to first contact tabsof one inter-row connector and the second battery terminals of allbatteries in the row are connected to the second contact tabs of anotherinter-row connector. The first battery terminals of the batteries in arow are at same electrical potential due to electrical interconnectionof the first battery terminals by the row tab of one inter-rowconnector. The second battery terminals of the batteries in the row areat same electrical potential due to electrical interconnection of thesecond battery terminals by the row tab of another inter-row connector.

After the battery modules have been assembled, the base plate 120 isattached to the battery modules to form a battery assembly 100. Thebattery assembly is mounted on the main housing and electricallyconnected to the battery management circuitry. When the battery assemblyis mounted, its top surface is proximal and facing the ceiling of thedischarge chamber. The example batteries of the example battery modulehave a safety vent which is adjacent the positive terminal, which is thefirst battery terminal. When the battery assembly is duly mounted, thefirst battery terminals of the battery are aligned on the top surface ofthe battery tray and are exposed to the air chamber and opposite-facingthe ceiling of the air chamber. As the safety vent

Before the battery assembly is mounted on the upper housing portion,thermal sensors are mounted on the discharge chamber to facilitatedetection of temperature inside the battery compartment. In thisexample, the venting apertures are formed on the top wall of the mainhousing and are symmetrically distributed on two sides of thelongitudinal center axis of the main housing. The venting apertures 232are distributed near the middle portion of the top wall of the upperhousing portion. The inner surface of the top wall defines the ceilingof the discharge chamber, which is also the ceiling of the batterycompartment since the discharge chamber is a portion of the batterycompartment in this example. A thermal sensor is mounted on the ventingapertures so that temperature inside the battery compartment can bemonitored and temperature of gaseous discharge which exits the batterycompartment through the venting apertures can be detected. In someembodiments, the thermal sensor may be mounted on other locations of thebattery compartment 106 or the discharge compartment 108 in alternativeor as an addition. The battery compartment is configured so that gaseousdischarge emanating from a battery of the battery module can only exitthrough the venting apertures. In example embodiments, the upper housingportion of the main housing is integrally formed of a non-air permeablematerial (hard plastics) with the venting apertures integrally molded.When the upper housing portion and the battery assembly are dulyassembled, the base plate and the upper housing portion cooperate toform an air-tight battery compartment except at the venting apertures.

To facilitate more accurate detection of temperature inside the batterycompartment, or more particularly the discharge chamber, which is theportion of the battery compartment intermediate the battery assembly andthe main housing, the upper housing portion is made of a thermallyinsulating material such as hard plastics so that the discharge chamberis thermally isolated from the ambient air to mitigate non-detection ofan abnormally high temperature due to heat exchange between air insidethe discharge chamber and ambient air through the upper housing portion,such heat exchange may cause a drop in temperature inside the batterycompartment and adversely affect accurate detection of adverse batteryconditions and timing of activation of counter-measures.

When the battery assembly is in place, the safety vents of the batteriesare proximal and exposed to the top surface of the battery assembly andto the discharge chamber. When the safety vent of a faulty batteryoperates to release hot gas from the battery, the hot gas inside thefaulty battery will exit from the top or top portion of the battery ashot gaseous discharge and move directly into the discharge chamber.

A battery may deteriorate and gradually become a faulty battery, forexample due to aging and weathering. When a battery becomes a faultybattery, it may begin to have a higher temperature and hot gas may emitfrom the battery. The initial rate of gaseous emission speed is usuallyrelatively low and the initial hot gas temperature is also relativelylow, for example, at between 100-120 degrees Celsius (° C.). When thetemperature of the battery increases further to a critical temperature,for example, the melting temperature of the electrode separator of abattery, melt down of the separator will expedite and aggravate batterydamage and the temperature of hot gas discharged by a faulty battery canrapidly reach 500 or 650 or even 800 or 1000 degrees Celsius. The hightemperature of a faulty battery can spread to adjacent batteries of thebattery module and may cause thermal runaway and possible explosion.Electrode separators are typically made of polyethylene, which has amelting temperature 133° C., or polypropylene, which has a meltingtemperature of 159° C. The melting temperature of the separator may betaken as a critical temperature for battery condition monitoring.

In some embodiments, a first cooling power may be applied when a firstactivation temperature is detected and a second higher cooling power maybe applied when a second, higher, activation temperature is detectedafter a predetermined time after activation of the cooling power to cooldown the battery assembly.

So that temperature inside the battery compartment can be detectedwithout having a thermal sensor for each battery, a number of thermalsensors, which is substantially smaller than the number of batteries, isdistributed to detect temperature inside the discharge chamber. Thethermal sensors in the present example are distributed inside thedischarge chamber and configured to detect temperature of the dischargecompartment, which is the portion of the battery compartment proximal tothe safety vents of the batteries and defining the discharge chamber.

To mitigate mixing of hot gas discharge emanating from a battery withair in the discharge chamber, the discharge chamber is configured sothat gaseous discharge can flow to a venting aperture in a shortdistance. For example, the venting apertures and the thermal sensors aredistributed on the ceiling of the discharge chamber so that hot gasemanating from a battery can travel upwards to the ceiling and then tothe venting aperture where or near where a thermal sensor is located.

To minimize distance that the hot gaseous discharge has to travel toreach a thermal sensor or a venting aperture, the axial extent of thedischarge chamber is configured to be substantially smaller than theaxial extent of the battery compartment. For example, the axial extentof the air chamber may be less than more than 5%, 10%, or 15% but lessthan 20%, 25% or 30% of the axial extent of the battery compartment. Theaxial extent of the discharge chamber may be less than 20%, 25%, 30% or40% and more than 5%, 10% or 15% of the axial extent of the batteryassembly.

So that hot gaseous discharge can be guided to move only through a shortdistance in the discharge chamber before reaching a closest thermalsensor or a closest venting aperture which is closest to the dischargingbattery, a plurality of fluid movement guides is formed on the ceilingto surround a venting aperture. Each fluid movement guide defines aguide track which is radially extending with respect to the ventingaperture and the guide tracks formed by a plurality of fluid movementguides define a plurality of tapered channels each of which tapers tonarrow on extending towards the venting aperture. The guide tracksextend orthogonally to the axial direction of the battery assembly,which is also the axial direction of the battery, and provides a guidefor the hot gaseous discharge to move from the safety vent of thebattery to the venting aperture 232 in a short distance and minimizemixing of the hot gas discharge with air of the air chamber so that thetemperature of the hot gaseous discharge is substantially maintainedwhen arrived at the thermal sensor, also known as temperature sensor.

The end tab portions 118 a of the inter-row connectors at the end rowsof the battery assembly are connected to power input and power outputterminals of the apparatus. The end tab portions of the inter-rowconnectors of the intermediate rows are connected to the batterymanagement circuitry to facilitate management of battery voltage at eachbattery row.

In example embodiments, the control circuitry is configured to monitortemperature of the batteries by monitoring temperatures at the pluralityof venting apertures, for example, by means of thermal sensors. When thetemperature detected at a venting aperture exceeds a predeterminedthreshold value, safety measures may be activated by the controlcircuitry. The safety measures may include shut down of a batterymodule, isolation of batteries or battery groups, for example, by fuses,or activation of cooling measures by operation of the fans. When batterycooling measures are activated within a short time of detecting an alerttemperature, movement of cooling air through the air compartment whichhopefully rapidly cool down a damaged battery or damaged batteries tobelow a critical temperature, above which the risks of battery melt downdue to thermal runaway may increase substantially.

In some embodiments, active cooling measures, for example, by use ofthermoelectric cooling devices such as Peltier devices may furtherexpedite the cooling process. The active cooling elements may beattached to the thermal exchange device and/or on the bottom portion ofthe main housing as a convenient example.

As the inter-battery connectors are directly connected to the batteryterminals, especially the battery terminal when a battery safety vent islocated, the network of inter-battery connectors functions as a heattransfer network for transfer heat from interior of the batteries to thethermal exchange device. Furthermore, the configuration of theinter-battery connectors, especially the configuration of theintermediate link portion as comprising exposed metal flaps also helpsto dissipate heat during normal operation of the battery assembly andhelps to maintain the battery to operate at preferred or desirableoperating temperatures.

During operations, if an activation temperature is detected by a thermalsensor, the control circuitry will activate counter-measures to cooldown the battery assembly to prevent or mitigate risks of thermalrunaway and possible meltdown. In example embodiments, once a criticaltemperature is detected by a thermal sensor, say 80° C. or 90° C., thefans will be activated to accelerate heat exchange between the batterymodule and the air in the air compartment and the process would help tocool down the battery assembly. In some embodiments, active thermalcooling may be used in addition or as an alternative. In someembodiments, external fans may be used and cold air may be supplied byan external source. The battery groups may also be shut down, forexample by fusible links upon detection of a critical temperature. Insome embodiments, the control circuitry may operate to shut down abattery module or the battery assembly when the temperature reaches asecond, higher temperature, say 100° C. A battery module may be shutdown, for example, by isolation by electronic switches such assemiconductor switches or fuses. In addition, the control circuitry maygenerate an alert signal when a critical temperature has reached. Thealert signal may include a local alarm on the apparatus and/or a remotealarm to be sent out of the apparatus, for example, via atelecommunication network through a telecommunication frontend of theapparatus.

A thermal exchange assembly of the present disclosure is configured as aheat sink, and more specifically, a distributed heat sink comprising adistributed heat transfer network formed by the inter-batteryconnectors. The thermal exchange assembly as a distributed heat sink hasan inherent ability to equalize temperature of batteries forming abattery module or a battery assembly. The temperature equalizing abilitycan be enhanced by active cooling by forced air movement or thermalelectric cooling to expedite thermal exchange with the thermal exchangeassembly.

Batteries typically have a specified operation temperature range, whichis defined between a minimum operation temperature and maximum operationtemperature. Most Li-ion cells are manufactured to operable below amaximum temperature of around 60˜65° C. An operation temperature whichis well below the maximum temperature is generally preferred for longerbattery life and longer-term safety.

The example apparatus may be configured so that the batteries are tooperate at a preferred operation temperature range which is anintermediate temperature range selected between the maximum temperatureand the minimum temperature. For example, the apparatus may beconfigured to operate so that the operation temperatures of thebatteries are kept at or below an upper temperature limit, say 40° C. or42° C. When batteries reach the upper temperature limit, the controlcircuitry will activate the cooling arrangement to bring the batterytemperatures down towards the lower limit of the intermediatetemperature range, for example, to bring down to the upper temperaturelimit or at a few degrees, say 1, 2, or 3 degrees, below, and theprocess will continue and repeated. In general, an intermediatetemperature range of between 25° C. and 42° C. has been found to bepreferable.

The control of battery operation temperature in an intermediatetemperature range which is selected between the maximum and minimumtemperatures requires more extensive and accurate battery temperaturemonitoring. To facilitate more extensive and accurate batterytemperature monitoring, a plurality of temperature sensors such astemperature probes are placed inside the battery receptacles to monitorbattery temperatures and control operation of the cooling arrangement bythe control circuitry.

The temperature sensors may be utilized to control temperatureimbalances among batteries of the battery assembly or module. Forexample, when a temperature imbalance exceeding an imbalance thresholdis detected, the control circuitry will operate the cooling arrangementto bring the battery temperatures down, wherein the temperatureimbalance is mitigated. An example imbalance threshold may be selectedas between 3-5° C. as a convenient example.

The heat transfer network comprises a matrix of thermal transfer memberswhich is physically connected to the battery assembly and extendsthrough the battery receptacles of the battery assembly. The thermaltransfer member has a first end which is physically connected to a firstbattery terminal of one battery and a second end which is connected to asecond battery terminal of another battery. The second end of thethermal transfer member is also connected to a main thermal exchangedevice, which is physically connected to an axial end of the batteryassembly. The main thermal device has a thermal contact surface which isin physical contact with the thermal transfer network but iselectrically insolated therefrom. The main thermal exchange device has athermal exchange surface which is physically connected with the thermalcontact surface for efficient heat transfer. In example embodiments, thethermal exchange surface and the thermal contact surface are oppositefacing major surfaces of a conductive plate such that the thermalexchange surface and the thermal contact surface are integrallyconnected by a thermally and electrically conductive material. In someembodiments, the thermal contact surfaces are delineated into aplurality of insulated or isolated electrically conductive regions andeach electrically conductive region is for making thermal but notelectrical contact with a group of heat transfer members such as anarray or of hear transfer members. The heat transfer members areconnected to thermal contact surface by a thermal conductive mediumwhich is electrically insulating to block electrical contact between theheat transfer network and the main thermal exchange device. The thermaltransfer members are arranged in arrays or rows and the arrays or rowsof thermal transfer members extend in an axial direction which isgenerally orthogonal to the thermal contact surface to form a3-dimensional heat transfer assembly. An example heat transfer member isalso a inter-battery connector comprising a first batter terminal tabwhich is in physical and electrical contact with a first batteryterminal and an inter-battery link which extends inside and through abattery receptacle to reach the thermal contact surface.

An example battery assembly 1100 comprises an example plurality ofbatteries connected in parallel and in series, as depicted in FIGS. 6and 6A. The plurality of batteries is held inside a battery tray whichis formed from a corresponding plurality of battery receptacles. Theexample battery tray comprises an example plurality of M=10 receptaclerows for receiving a corresponding plurality of M=10 receptacle rows ofbatteries, with each row comprising an example plurality of N=5 batteryreceptacles for receiving a corresponding plurality of N=5 receptaclerows of batteries. Each example receptacle row is formed by two modularmembers, for example, made of hard plastics and by snap-fitting, asdepicted in FIGS. 7A and 7B. An adjacent pair of rows of batteries,consisting of two rows of batteries, are connected in series by aninter-row connector, as shown in FIG. 7C. Each inter-row connectorcomprises a plurality of N inter-battery connectors and eachinter-battery connector comprises a first battery terminal contact tab1112, a second battery terminal contact tab 1114 and an inter-terminaltab 1116 which interconnects the first battery terminal contact tab 1112and the second battery terminal contact tab 1114, as shown in FIG. 8 . Awindow or aperture, which extends for a substantial portion of the axiallength of the inter-battery connector is formed on the inter-terminaltab 1116.

To assemble a battery row of batteries in parallel, an inter-row batteryconnector is attached to a plurality of batteries forming a battery row,as depicted in FIG. 7B, and the modular members are fitted together toform a sub-assembly of FIG. 7A. When the battery row is assembled, thefirst battery terminal contact tab 1112 is on a first axial end of thebattery receptacle and in physical and electrical contact with the firstbattery terminal, the second battery terminal contact tab 1114 projectsfrom the second end of the battery receptacle and extends into anotherrow for making physical and electrical contact with the second batteryterminal of a battery in another row, and the inter-terminal tab 1116extends axially inside the battery receptacle between the first axialend and the second axial end of the battery receptacle of the batteryhaving its first terminal connected with the first battery terminalcontact tab 1112. The batteries and the battery receptacles forms abattery module which is received inside a metal casing 1122, the metalcasing has a bottom portion having an inner surface which is in thermalcontact with the second battery terminals of the batteries forming thebattery module and the bottom portion is functionally equivalent to thebase plate 112 of the example apparatus of FIG. 1 .

In the example battery assembly 1110 of FIG. 6 , the battery rows areorganized in the form of a rectangular matrix so that the plurality ofbatteries are arranged into rows and columns, wherein a column isorthogonal to a row. In such example embodiments, the first batteryterminal contact tab 1112 and the second battery terminal contact tab1114 are laterally aligned, that is, aligned in the direction of acolumn or Y-direction, although the first battery terminal contact tab1112 and the second battery terminal contact tab 1114 are on oppositesides of the inter-terminal tab 1116.

Where batteries forming a battery module or a battery assembly are notaligned in a rectangular matrix, the first battery terminal contact taband the second battery terminal contact tab will be laterally offsetwithout loss of generality, for example, as depicted in FIGS. 9 and 9A.

Apart from the differences, the inter-row connector 1110 is similar tothe inter-row connector 110 and the description herein in relation tothe inter-row connector 110 is incorporated herein by reference and isto apply mutatis mutandis, with numeral values increased by 1000.

While the present disclosure is described with reference to embodiments,the embodiments are non-limiting implementation examples. For example,while the example battery module comprises cylindrical batteries,non-cylindrical batteries may be used to build the battery assemblywithout loss of generality. While the example apparatus comprises an aircompartment to define a path for air circulation and a fan compartmentto move air, the air compartment and the fans and/or compartment are notessential. For example, the thermal exchange surface may be exposed toambient air and air may be circulated by external air movingarrangements without loss of generality. While the main housing of theexample apparatus comprises an upper housing portion and a lower housingportion, there is no limitation in the placement direction and the mainhousing may be partitioned or oriented in other directions. For example,the upper housing may be the lower housing, the lower housing may be theupper housing and the main housing may comprise left housing and righthousing without loss of generality. Furthermore, while the battery traysprovide a robust structure to hold the batteries of the example batteryassembly, the batteries may be mounted on other holding structureswithout loss of generality.

The invention claimed is:
 1. A battery assembly comprising a thermalexchange device and a plurality of batteries arranged into a pluralityof battery groups, wherein the battery group comprises a plurality ofbatteries in parallel connection and the battery groups are connected inseries by a plurality of inter-battery connectors, wherein the thermalexchange device comprises a thermal contact surface which is in thermalcontact with a heat transfer network, and a thermal exchange surfacewhich is configured to perform heat exchange; wherein the heat transfernetwork comprises the plurality of inter-battery connectors which are inelectrical contact with battery terminals of the batteries forming thebattery assembly, wherein the inter-battery connectors are in physicaland thermal contact with the thermal contact surface of the thermalexchange device to facilitate transfer of heat from the batteryterminals to the thermal contact surface and are electrically insulatedfrom the thermal exchange surface or the thermal exchange device; andwherein the inter-battery connector comprises a first terminal tab whichis physically joined to a first battery terminal of a battery, a secondterminal tab which is physically joined to a second battery terminal ofanother battery, and an inter-terminal tab electrically interconnectingthe first terminal tab and the second terminal tab; and wherein thefirst battery terminal and the second battery terminal are batteryterminals of opposite electrical polarity.
 2. The battery assemblyaccording to claim 1, wherein the battery assembly comprises a pluralityof battery groups and batteries of an adjacent pair of battery groupsare electrically connected by an inter-battery group connector; whereinthe inter-battery group connector is formed by a plurality ofinter-battery connectors connected in series, and the inter-batterygroup connectors are connected to form a heat transfer network.
 3. Thebattery assembly according to claim 1, wherein the plurality ofinter-battery connectors of the battery assembly is arranged into aplurality of heat transfer gratings, and the plurality of heat transfergratings are connected to form the heat transfer network.
 4. The batteryassembly according to claim 3, wherein each heat transfer grating is ametal grating formed by a plurality of inter-battery connectors inelectrical interconnection.
 5. The battery assembly of claim 1, whereinthe inter-terminal tab is a metal flap comprising a first metal flapportion, a second metal flap portion and an intermediate metal flapportion which electrically interconnects the first metal flap portionand the second metal flap portion; wherein the first metal flap portionis electrically connected with the first terminal tab and the secondmetal flap portion is electrically connected with the second terminaltab; and wherein the first metal flap portion, the second metal flapportion and the intermediate metal flap portion are integrally formed;and/or wherein intermediate metal flap portions of adjacentinter-battery connectors forming an inter-battery connector group areintegrally interconnected.
 6. The battery assembly according to claim 1,wherein the first terminal tab projects in a first projection directionaway from the inter-terminal tab and the second terminal tab projects ina second direction away from the inter-battery link, the firstprojection direction and the second projection direction being oppositedirections; and/or wherein the first terminal tab projects orthogonallyaway from the inter-terminal tab to form a first contact plane and thesecond terminal tab projects to form a second contact plane parallel tothe first contact plane.
 7. The battery assembly according to claim 1,wherein the first terminal tabs of the plurality of batteries define afirst surface of the battery assembly and the second terminal tabs ofthe plurality of batteries define a second surface of the batteryassembly which is parallel to the first surface, wherein the pluralityof batteries is intermediate the first surface and the second surface,and wherein the first battery terminal and the second battery terminalare of opposite electrical polarity; and/or wherein the battery assemblycomprises a plurality of battery rows, each battery row comprising aplurality of batteries organized into a row; and wherein theinter-terminal tabs of batteries of a battery row are electricallyconnected to form a heat transfer grating of metal flaps.
 8. A powersupply apparatus comprising a main housing, battery managementcircuitry, a thermal exchange arrangement and the battery assemblyaccording to claim 1; wherein the main housing comprises a batterycompartment in which the battery assembly is held; wherein the thermalexchange arrangement comprises a thermal exchange device whichpartitions the main housing into the battery compartment, and whereinthe thermal exchange arrangement is configured to facilitate exchange ofheat across a boundary or a partition panel of the battery compartment.9. The power supply apparatus according to claim 8, wherein the mainhousing comprises a first housing portion which surrounds the batteryassembly and which defines a vented compartment above the batteryassembly, the vented compartment comprising a plurality of ventingapertures to permit gaseous discharge emanated from the battery assemblyto escape out of the battery compartment; and wherein a plurality ofthermal sensors is distributed on the vented compartment; and/or whereinthe thermal exchange surface is an outward-facing major peripheralsurface of the battery compartment which faces away from the batteryassembly and which is exposed to air.
 10. The power supply apparatusaccording to claim 8, wherein the main housing comprises a thermalexchange compartment which is in abutment with the battery compartment,and wherein the thermal exchange surface is a boundary surface of boththe air compartment and the battery compartment.
 11. The power supplyapparatus according to claim 10, wherein the main housing comprises asecond housing portion which cooperates with the thermal exchangesurface to define the thermal exchange compartment; and wherein thesecond housing portion is thermally conductive and in thermalcommunication with ambient air.
 12. The power supply apparatus accordingto claim 11, wherein the main housing comprises a fan compartment whichis in fluid communication with the thermal exchange and installed withan air moving device, and wherein the second housing portion form partsof the fan compartment.
 13. The power supply apparatus according toclaim 8, wherein a plurality of thermal sensors is disposed at acorresponding plurality of venting apertures, and the vented compartmentis thermally insulated from ambient temperature.
 14. The power supplyapparatus according to claim 8, wherein the thermal exchange devicecomprises a thermally conductive plate which physically partitions aportion of the main housing into the battery compartment, wherein thethermal contact surface and the thermal exchange surface areopposite-facing major surfaces of the thermally conductive plate, andwherein the plurality of inter-battery connectors are in physical andthermal contact with the thermal contact surface of the thermallyconductive plate and are electrically insulated therefrom to form theheat transfer network.
 15. The power supply apparatus of claim 14,wherein the thermally conductive plate physically partitions the portionof the main housing into the battery compartment and a thermal exchangecompartment, and wherein thermal exchange compartment is in fluidcommunication with a fan compartment of the main housing.
 16. The powersupply apparatus of claim 14, wherein the thermally conductive plate isan electrically conductive plate, and the thermal contact surface isimprinted with a plurality of thermally and electrically conductivetracks; and wherein a conductive track is in physically and thermallyjoined to a group of inter-battery connectors, the group ofinter-battery connectors comprising inter-battery connectors of a groupof parallel connected batteries.
 17. The power supply apparatus of claim16, wherein a conductive track is electrically isolated from anotherconductive track by an electrical insulator surrounding the conductivetrack or by an electrical insulator separating the conductive track andan adjacent track or adjacent conductive tracks.
 18. The power supplyapparatus according to claim 8, wherein a plurality of thermal sensorsis distributed inside the battery assembly to detect temperatures ofbatteries of the battery assembly, wherein the thermal sensors areconfigured to deliver temperature information to the battery managementcircuitry, and wherein the battery management circuitry is configured toactivate a temperature conditioning arrangement when temperatures of thebatteries have a difference reaching a predetermined temperaturedifference threshold or reaching a predetermined temperature limit. 19.The power supply apparatus according to claim 18, wherein thetemperature conditioning arrangement is configured to expedite thermalexchange operations of the thermal exchange arrangement when activated;and/or wherein the temperature conditioning arrangement comprises anair-driving arrangement and/or a thermo-electric arrangement, andwherein the air-driving arrangement and/or the thermo-electricarrangement is configured to interact with the thermal exchange deviceto expedite thermal exchange; and/or wherein the battery managementcircuitry is configured to operate the temperature conditioningarrangement to equalize temperatures of the batteries of the batteryassembly to within an operation range or a temperature difference.